1. Technical Field
The present invention relates to a light irradiation device, and an image forming apparatus including the light irradiation device.
2. Description of the Related Art
The recent image reading devices irradiate a document placed on a document table with light outputted from a light source and read a document surface based on light reflected by the document. Such an image reading device includes a light irradiation device structured to irradiate the document surface, at an irradiation point thereon, with light in two different directions. The irradiation point is irradiated with light in the two directions, so as to prevent occurrences of shadows on the document surface. In other words, if the document surface is irradiated with light only in a single direction, the document-reading quality may be degraded, due to shadows induced on the document surface. In order to prevent this, the document surface is irradiated with light in two directions.
In order to irradiate the document surface with light in two directions, a light guide member for guiding light outputted (emitted) from the light source to the irradiation point is used. As such light guide members, there have been known light guide members provided with two emission surfaces (a first emission surface and a second emission surface). Light emitted from the first emission surface is directed to the irradiation point, using a reflection surface. Further, light emitted from the second emission surface is directly directed to the irradiation point.